The disclosed embodiments of the present invention relate to a turbo decoder design, and more particularly, to an adaptive multi-core, multi-direction turbo decoder and related decoding method thereof.
Data signals, in particular those transmitted over a typically hostile channel, are susceptible to channel noise/interference. Various methods of error correction coding have been developed in order to minimize the adverse effects that a hostile channel has on the integrity of the transmitted data. This is also referred to as lowering the bit error rate (BER), which is generally defined as the ratio of incorrectly received information bits to the total number of received information bits. Error correction coding generally involves representing digital data in ways designed to be robust with respect to error bits. Hence, error correction coding may enable a communications system to recover original data from a signal that has been corrupted due to the undesired channel noise/interference. For example, turbo codes may be used in the communications system, such as a Wideband Code Division Multiple Access (WCDMA) system and a Long Term Evolution (LTE) system, for channel coding.
Regarding any LTE system, it is desirable to find a way to support high data throughput. One conventional design is to use multiple turbo decoders, each having a single maximum a-posteriori probability (MAP) core. It is a straightforward method to increase the throughput but is out of date. Besides, multiple single-core turbo decoders will increase the cost by additional overhead and complicate the whole system design.
Another conventional design is to use a single turbo decoder with multiple MAP cores, each operating on a portion of the target code block. However, all of the MAP cores operate in the same decoding direction for computing forward/backward metrics will slow down the memory passing rate to affect performance and power consumption of the turbo decoder. Thus, there is a need for a turbo decoder with multiple MAP cores and multiple decoding operations for both performance and cost efficiency.